Hi, how do you get rid of ants that are proliferating on a Weeping Birch(I think that is what this tree is... And, is it detrimental to the health of the tree?
Re: Ants on Weeping Birch Looks like the leaves of an elm in your picture. If there is a another part of the tree that is a dense dome of weeping branches with broader leaves then you have a Camperdown elm and the shoots in your picture are probably rootstock sprouts that should be cut off. It would become possible to tell if that is the situation if you showed picture(s) of the whole tree. The black sections on the leaves may be sooty mold fungus growing on the sugary waste of sucking pests such as aphids. This is liable to be what has attracted the ants, they like sugar. The holes will be produced by a chewing insect such as a caterpillar. If none of these last are visible anywhere on the tree now they may have moved along in their life cycle.
Hi RonB, Thanks for the reply. I've confirmed that the tree is an Ulmus glabra 'Camperdownii'. Good eye! I initially thought the holes were caused by the ants but as long as they don't damage the tree then it's okay until I find a way to get rid of them. So far, some ant traps are placed at the root of the tree but I'm not sure that is doing anything. I took a photo of the whole tree and the bottom leaves. Should they be trimmed... and which part? Appreciate your input! :)
The ants are almost certainly merely coming to "milk" aphids or other sucking pests and are otherwise of no consequence. If you want to clear out the bugs identify and control the sucking pests and the ants will not be coming around so much. And of course if chewing insects are still present and making holes you would want to locate, identify and eliminate those to stop additional chewing. However, all this will be incidental to the fact that the tree is suffering in a baking and perhaps infertile planting site where it clearly needs to be mulched, thoroughly watered and perhaps fertilized. Distressed trees attract pest insects so it is possible you will see fewer bugs on it when you start improving its growing situation. The Camperdown elm is liable to be sitting on top of the trunk and roots of another kind of elm. So you would cut off any sprouts that come from the trunk and below, while leaving all the branches that have the correct leaves and orientation for the Camperdown elm. These leaves should all be broader relative to their length than those of the rootstock and be borne on arching branches that point to the ground near their ends.
Take a hose & wash the leaves fairly strongly on daily basis. Not to water the plant, but to control the aphids by knocking them off...and thus controlling the ants. Water the tree deeply - a trickling hose left for 1/2 hour at a couple of spots around the base is my way of doing that.
